Clostridium acetobutylicum

Clostridium acetobutylicum, included in the genus Clostridium, is a commercially valuable bacterium. It is sometimes called the "Weizmann Organism", after Chaim Weizmann, who in 1916 helped discover how C. acetobutylicum culture could be used to produce acetone, butanol, and ethanol from starch using the ABE process (Acetone Butanol Ethanol process) for industrial purposes such as gunpowder and Cordite (using acetone) production. The A.B.E. process was an industry standard until the late 1940s, when low oil costs drove more-efficient processes based on hydrocarbon cracking and petroleum distillation techniques. C. acetobutylicum also produces acetic acid (vinegar), butyric acid (a substance that smells like vomit), carbon dioxide, and hydrogen.

Anaerobic fermentation using C. acetobutylicum recently regained marked interest for use in vehicle biofuel production as a gasoline and diesel fuel replacement. This is because butanol, as produced by a fibrous bed bioreactor utilizing recent biotechnology co-developed by Environmental Energy Inc. and Ohio State University, produces the alcohol butanol as its primary output. The patented process using C. tyrobutyricum produces little acetone or ethanol, instead producing butyric acid and hydrogen, which is then pumped into another fibrous bed bioreactor where C. acetobutylicum converts the butyric acid into butanol, thus optimizing butanol production. The new process, then, obviates the A.B.E. process, making butanol production competitive with other biofuels with regard to both economics and energy production.

Pure butanol can be utilized in gasoline-powered cars without any modifications, producing similar mileage performance to gasoline but producing fewer NOx pollutants. If produced from a biomass source, there is no net carbon dioxide production.

Unlike yeast, which can digest sugar only into alcohol and carbon dioxide, C. acetobutylicum and many other Clostridia can digest whey, sugar, starch, lignin, cellulose fiber^{[dubious – discuss]}, and other biomass directly into butanol, propionic acid, ether, and glycerin. Apart from the need for temperature control, the A.B.E. synthesis process is relatively simple. The products are formed in layers that are easy to separate.

Biobutanol supporters claim significant advantages over other biofuels used to fuel internal combustion engine vehicles (ICEVs) and other liquid-fueled processes:

• Butanol has a higher octane fuel value than gasoline with increased low-end torque. A V8 engine has been tested on a 10,000-mile U.S. tour supporting a U.S. Department of Energy grant in 2005. The results of the butanol auto fuel demonstration were presented to the U.S. Department of Energy National Renewable Energy Laboratory's Clean Energy Forum in San Francisco on November 7, 2005.
• Butanol does not readily adsorb moisture (it is not hygroscopic), so is less affected by changes in the weather, unlike the combustion of pure ethanol, which requires engine and fuel system modifications.

• Butanol does not attack materials commonly used in vehicular internal combustion engines.
• Biobutanol can also be used in the industrial paint and solvent industry to replace fossil butanol.

James Liao, a chemical engineer at the University of California, Los Angeles, developed a method to insert genes from Clostridium acetobutylicum which are responsible for production of butanol into the bacterium Escherichia coli. [1] [2]

See also

• Algal fuel
• Biobutanol

References

This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed. (July 2008)

Further reading

• Nölling J, Breton G, Omelchenko MV, et al. (August 2001). "Genome sequence and comparative analysis of the solvent-producing bacterium Clostridium acetobutylicum". J. Bacteriol. 183 (16): 4823–38. doi:10.1128/JB.183.16.4823-4838.2001. PMID 11466286. 
• Driessen AJ, Ubbink-Kok T, Konings WN (February 1988). "Amino acid transport by membrane vesicles of an obligate anaerobic bacterium, Clostridium acetobutylicum". J. Bacteriol. 170 (2): 817–20. PMID 2828326. PMC: 210727. http://jb.asm.org/cgi/pmidlookup?view=long&pmid=2828326. 
• Zappe H, Jones WA, Jones DT, Woods DR (May 1988). "Structure of an endo-beta-1,4-glucanase gene from Clostridium acetobutylicum P262 showing homology with endoglucanase genes from Bacillus spp". Appl. Environ. Microbiol. 54 (5): 1289–92. PMID 3389820. PMC: 202643. http://aem.asm.org/cgi/pmidlookup?view=long&pmid=3389820. 
• Bowles LK, Ellefson WL (November 1985). "Effects of butanol on Clostridium acetobutylicum". Appl. Environ. Microbiol. 50 (5): 1165–70. PMID 2868690. PMC: 238718. http://aem.asm.org/cgi/pmidlookup?view=long&pmid=2868690. 

External links

• findarticles.com: Bacteria speeds drug to tumors - use of Clostridium acetobutylicum enzyme to activate cancer drug CB 1954.
• EPA Clostridium acetobutylicum Final Risk Assessment
• Carolina Bio Supply Living Culture Order Page
• Environmental Energy Inc.
• Genetic Engineering of Clostridium acetobutylicum for Enhanced Production of Hydrogen Gas: Penn State University.
• Pathema-Clostridium Resource
• US Patent 1,875,536, issued September, 1932, Wheeler et al.
• US Patent 1,315,585, issued September, 1919, Weizmann